To Err is Human
by proxydialogue
Summary: Castiel has an enlightening conversation with The Devil. Spoilers for 7.17 do live here


__**A/N**: Beta'd by scarletjedi. Written as catharsis for my 7.17 feels. And as such, here there be  
SPOILERS! Up to and including 7.17

__**To Err is Human**

_to forgive, divine._

He wears the smiling and kind face of his vessel and sits on the table with his feet on the chair.

"It's a little bit…ironic, isn't it?" Lucifer drawls. Cas folds his hands and squeezes them between his thighs to keep them warm. His fingers are always freezing. "I mean, you're practically one of the _family_, right? All Winchesters gotta go to Hell."

Cas stares at his brother's feet. He won't look at Lucifer's face. His eyes are empty and they remind him of something horrible. Something cruel. Something he lived for, once up a time…

_Don't think about it._

"Although, it's a little unfair if you think about it. I mean, Sam and Dean only had to go to hell once. How many times have you been now?" Fingernails on drywall, scraping. He can feel the peeling of the wall like it's the walls of his lungs and skull. The white dust floating down to the table top. Soon the daylight will shine on the blood vessels and bones beneath his temple. Cas raises his hand to his head and wipes the sweat away. He is relieved when his fingertips come away clean.

His mind hasn't begun to seep out of the holes in his head yet.

The scraping continues.

"_Three._ If you count this, and I think we can. Home is where the heart is, right?" A chunk of the wall clatters to the floor. It sounds like the sky falling, like the frame of the earth crumbling. Cas takes his freezing, shaking hands out of his lap and holds his poor head. "_Wow_ that first trip was a pleasure cruise. Remember the screams?" Lucifer whoops and claps his hand. "You thought they tasted like wet ash. You must have already been on your way earthbound by then, it's really kind of _human_ to make comparisons. Oh! And the smell! Frying flesh and your own wings burning. It sounded like music." Cas peeks at his brother through his fingers. The scraping has stopped and Lucifer is waving his fingers through the air as if he can hear violins.

Lucifer begins to sing and it sounds just like Hell. Cas claps his hands over his ears but it's too late, the sound is inside and he can't keep it away.

It's beautiful. It brings tears to his eyes.

"Dean's white teeth," Lucifer interrupts himself and the song jars to a stop. "Kid was grinning from ear to ear."

_He was more beautiful than the music._

"I continue to be impressed by you Castiel," Lucifer croons. "You do know what real beauty is. That's your curse, isn't it? All that time floating around with your pansy-ass brothers while they talked about symmetry and angles. Didn't it drive you _nuts?_"

The chair screeches across the floor as Lucifer gets up. He stretches himself languidly, Cas can hear his spine popping.

"Ah," Lucifer walks over and sits down beside him. "And the second trip?" he prompts. Cas is very careful not to answer. His brother is not real, but the conversation could be, and that is what frightens him. "Alright, I don't mind doing all the work in this relationship.

"The second time was better. Further away from the fire, below the harpsichords and cellos; _aaaaaalllllll_ the way down." Lucifer leans close and Cas feels the brush of the lips in his hair as Lucifer whispers, "Silence." Air across his neck, the trailing gentle touch of a fingertip. "It was like peace down there. It was like sleep." A blissfully cool palm across the back of his neck, thumb caressing the base of his skull. Cas tips his head back. "You wanted to stay," Lucifer says softly. "You wanted to curl up around our boy Sam and lay in the dark while the ice ate your wings away."

Cas' face is wet. He lets the water run out of his body through his eyes. He wants to be empty.

"But you pulled him out anyway, for Dean. And _that_ didn't go very well, in the end." Lucifer helps to wipe the tears away. "Now here you are again. You just keep coming back to me, Castiel." The cool hands cup his jaw and draw Cas' face up, he looks into the dark eyes of his brother. Terrible eyes. Eyes with anger and hate. _Dean's eyes._ Cas swallows. "What do you think of me little brother?" Lucifer asks and his voice is vulnerable.

_Don't answer._ But his will is gone. He's cried it out.

"I think you're beautiful," Cas whispers. A grin lights up Lucifer's face.

"I knew it," he says. "You're not too shabby yourself," Lucifer ruffles his hair and lets him go. The room feels unbearably warm without the touch of his hands. Lucifer scratches idly at the rough sheets of the bed. "Would you like me to explain everything to you? You've been all knotted up for years, but I can fix that."

_Don't speak. Don't utter your lies. Please brother._

"You're in love you little tit." Inside, where the pits are and the memories of beautiful music, Cas is unwinding. Relief crawls up his spine. Tension he hadn't been aware of flows out of his chest and his shoulders. "There," says Lucifer. "That's not so bad, is it? Even Dad would approve, I bet. Dean is a righteous man, good soul, good intentions most of the time." Lucifer leans back on his hands and stares at Cas with amusement. "You sure know how to pick'em."

The sunlight through the window is burning Cas' back. He looks up to his shadow on the wall and stretches the cramps in his wings, unfolds them slowly and with care. The light shines through the rips and imperfections. Tatters. Lucifer looks at them too.

"You've been through Hell, sweetheart."

They sit together, shoulder to shoulder, like equals.

"Would you like me to tell you how to get out?" Lucifer asks. Cas doesn't bother saying, "Yes." He waits instead. He is very good at waiting. Lucifer reaches over and taps the place over Cas' heart. It travels through Cas' bones like a hammer strike. "All you have to do is forgive me."

Horror in his belly.

He looks at Lucifer.

"Impossible," he croaks. "It's not my place. You've killed thousands. You've tortured. You broke Heaven apart and set evil upon the world."

Lucifer's grin, this time, is not so kind. Lucifer waits. He is very good at waiting.

"You're not real, anyway," Cas tell him. "You are my mind. You are my insanity. How can I forgive you? You are me."

Lucifer's laugh splits his tongue like storms split the sky. Thunder before the rain.

"How can you forgive yourself?" he agrees. "Hell if I know."


End file.
